The present invention relates to an antibacterial deodorant, and more particularly to an antibacterial deodorant which shows the antibacterial effect, deodorizing effect, and mildewproof capability when added in or applied to resins, paints, textiles, paper, unwoven cloths, leather, furniture, cosmetics, glass, tile, concrete, and the like.
There have been known antibacterial compositions comprising a metal component having the antibacterial characteristics carried on powder of such materials as zeolite, silica gel, or titanium oxide, and the antibacterial compositions are disclosed, for instance, in Japanese Patent Laid-Open Publication No. HEI 2-225402 (Patent document 1).
However, the known powder antibacterial compositions have the problems as described below:
(1) the dispersibility is low when added in resins, paints, textiles, leather, cosmetics, and the like;
(2) the antibacterial capability is not expressed effectively, and it is necessary to add the antibacterial composition by a large volume for obtaining the desired antibacterial activity;
(3) the powder easily aggregates when the added volume increases, and further as a content of the metal component increases, the color change may occur in the composition using an antibacterial metal component such as silver;
(4) when the antibacterial composition is added in a resin as a raw material for fiber spinning, thread breakage easily occurs when the thread is produced with composition powder with a large diameter;
(5) when a paint containing the antibacterial composition in the powder state is applied on a surface of a material such as a resin for forming a coating film with the antibacterial capability, the film thickness is large and the film strength is rather low, and in addition film peeling easily occurs. Further the composition can not be used when the transparency is required;(6) the film peeling easily occurs also when a paint containing the antibacterial composition in the powder state is applied to a surface of leather or the like, and the texture and color may sometimes be undesirable.
The present inventors proposed, in Japanese Patent Laid-Open Publication No. HEI 3-275627 (Patent document 2), a novel antibacterial composition prepared by exchanging metal ions in a salt of inorganic oxo acid with ions of metal having the antibacterial characteristics, but the composition cannot always satisfy the requirements for solving the problems described above.
Japanese Patent Laid-Open Publication No. HEI 1-258792 (Patent document 3) proposes an antibacterial agent containing alumina sol having the antibacterial characteristics with a metal having an antibacterial function or a compound thereof deposited on a surface of aluminum oxide in the alumina sol. It can be guessed that the invention dissolves the problem (5) making use of a coating film forming-function possessed by alumina sol, but the problems (1) to (4) are still kept unsolved.
Further Japanese Patent Laid-Open Publication No. HEI 4-321628 (Patent document 4) proposes an antibacterial agent comprising silver colloidal particles having the high antibacterial performance, but the colloidal solution has a grey color and lacks the transparency. In addition, the silver component itself is colloidal particles, and therefore there is the problem that the antibacterial agent easily aggregates and lacks the stability.
To solve the problems specific to the antibacterial composition or deodorizing compositions in the power state as described above, the present inventors proposed, in Japanese patent Laid-Open Publication No. HEI 6-80257 (Patent document 5) and Japanese Patent Laid-Open Publication No. HEI 7-33616 (Patent document 6), an antibacterial agent comprising a novel colloidal solution of antibacterial inorganic oxide.
Japanese Patent Laid-Open Publication No. HEI 7-33616 (Patent document 6) proposes an antibacterial inorganic oxide colloidal solution in which particles comprising an antibacterial metal component and an inorganic oxide other than the antibacterial metal component are dispersed, and the antibacterial inorganic oxide colloidal solution is characterized in that, assuming A indicating a weight of the antibacterial metal component in the colloidal solution and B indicating a weight of the antibacterial metal component segregated by subjecting the colloidal solution to the ultra-centrifugal processing, a value for an index of coupling expressed by B/A is 1.0×10−3 or below, and discloses a method of preparing the antibacterial agent by heating an aqueous solution of titanium oxide obtained by adding hydrogen peroxide in a gel or a sol of hydrated titanic acid and an aqueous solution of an antibacterial metal component in the presence of a silicon compound and/or a zirconium compound.
The problems (1) to (6) have been solved by the inventions above to some extent, but sometimes the odor eliminating performance is insufficient, thus, in some applications, an antibacterial deodorant having the further sufficient odor eliminating performance is needed. Especially, the so-called sick house syndrome is seen as a social problem in relation to the living environment or residential environment, and deodorants are required to have the capability of killing ticks, fleas, and the like, the capability of decomposing odorous organic compounds such as aldehyde, toluene, xylene, and further the capability of eliminating harmful gasses such as carbon monoxide and organic materials such as tar generated in association with smoking.
To clean the living environment as described above, there has been proposed a method of producing various types of antibacterial agents and deodorants each including titanium oxide having the photocatalytic effect.
For instance, Japanese Patent Laid-Open Publication No. 2004-91263 (Patent document 7) proposes a method of producing a anatase-type titania sol comprising the steps of mixing an aqueous solvent solution of a titan compound expressed by the formula of TiX4 (X indicates an halide ion or an alkoxy group) to generate titanium hydroxide; mixing the titanium hydroxide with an acid; and heating the mixture to a temperature in the range from 20 to 90° C., and this document includes descriptions concerning the fact that the anatase-type titania has the photocatalytic characteristics such as the antibacterial activity, decontaminating capability, and odor eliminating characteristics. However, because the anatase-type titania sol does not include any antibacterial and odor-eliminating metal component, the antibacterial activity and odor-eliminating effect are disadvantageously small.
The present inventors proposes in Japanese Patent Laid-Open Publication No. HEI 10-17406 (Patent document 8) an antibacterial agent comprising a colloidal solution with fiber-like inorganic oxide particles including titanium oxide dispersed therein as an antibacterial agent having the excellent durability against, for instance, washing. However, the titanium oxide included in this antibacterial agent is amorphous titanium oxide, and as the fiber-like particles are dispersed in the colloidal solution, when this antibacterial agent is used for textile, the fiber-like colloidal particles show a strong adhesive force without using any binder.    [Patent document 1] Japanese Patent Laid-Open Publication No. HEI 2-225402    [Patent document 2] Japanese Patent Laid-Open Publication No. HEI 3-275627    [Patent document 3] Japanese Patent Laid-Open Publication No. HEI 1-258792    [Patent document 4] Japanese Patent Laid-Open Publication No. HEI 4-321628    [Patent document 5] Japanese Patent Laid-Open Publication No. HEI 6-80527    [Patent document 6] Japanese Patent Laid-Open Publication No. HEI 7-33616    [Patent document 7] Japanese Patent Laid-Open Publication No. 2004-91263    [Patent document 8] Japanese Patent Laid-Open Publication No. HEI 10-17406